ack regex：在同一行中按顺序匹配两个单词 [英] ack regex: Matching two words in order in the same line

问题描述

我想在文件中依次包含两个单词，分别为 word_1 和 word_2 的行，例如在下面的 A行中，但与在 B行或 C行：

I would like to find lines in files that include two words, word_1 and word_2 in order, such as in Line A below, but not as in Line B or Line C:

Line A: ... word_1 .... word_2 .... 
Line B: ... word_1 ....
Line C: ... word_2 ....

我尝试过

$ack '*word_1*word_2'
$ack '(word_1)+*(word_2)+'

以及与 ^ 附加在正则表达式的开头（试图遵循Perl正则表达式的语法）。

and the same commands with ^ appended at the beginning of the regex (in an attempt to follow the Perl regex syntax).

这些命令都不返回我感兴趣的文件或行

None of these commands return the files or the lines I am interested in.

我在做什么错了？

谢谢！

推荐答案

您要查找 word_1 ，后跟任意次数，任意次数，后跟 word_2 。应该是

You want to find word_1, followed by anything, any number of times, followed by word_2. That should be

word_1.*word_2

您似乎正在使用 * ，因为它经常在命令行搜索中使用，但在正则表达式中它是前一个字符的量词，表示至少匹配0次。例如，正则表达式 a * 将匹配0个或多个 a s，而正则表达式 a + 至少匹配一个 a 。

You seem to be using * as it is often used in command line searches, but in regexes is it a quantifier for the preceding character, meaning match it at least 0 times. For example, the regex a* would match 0 or more as, whereas the regex a+ would match at least one a.

正则表达式元字符的意思是匹配任何内容是。，所以。* 的意思是匹配任何次数，任何次数。请参阅 perlrequick ，以简要介绍该主题。

The regex metacharacter meaning "match anything" is ., so .* means "match anything, any number of times. See perlrequick for a brief introduction on the topic.

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